Easiest is the plain swap for manny tranny and 615.Putting the 617 in is more complicated, as you need different front springs and a different drive shaft -- at least the front half. Tranny will bolt right up, linkage will work, etc, but the driveshaft is shorter, probably have a hard time finding one (although the 615 auto driveshaft may fit the 617 manny tranny).
Peter
